马氏体不锈钢低温等离子体稀土氮碳共渗研究

Low temperature plasma RE nitrocarburizing of martensitic stainless steel

将17-4PH马氏体不锈钢在430℃进行了有无稀土添加的等离子体氮碳共渗处理,其利用OM、XRD、显微硬度计和摩擦磨损试验机研究了共渗动力学、渗层组织结构、硬度以及摩擦磨损行为。结果表明,添加稀土使共渗层组织更加致密,渗层增厚;添加稀土不改变渗层的表面相结构组成,即主要由含氮碳膨胀马氏体(α'N)、γ'-Fe4N和CrN相组成;添加稀土可使氮碳共渗层厚度增加46%以上,渗层显微硬度可提高100 HV0.1左右,同时明显提高耐磨性能。

Plasma nitrocarburizing of 17-4PH martensitic stainless steel was conducted at 430 ℃ with or without rare earth（RE） addition.The growth kinetics,microstructure,hardness and wear resistance of the modified layer were studied by using the OM,XRD,microhardness and pin-on-disc tribometer.The results show that the RE nitrocarburized layer is more compact than that formed by nitrocarburizing without RE addition.The RE does not change the surface phase composition and the nitrocarburized layer consists mainly of nitrogen and carbon expanded martensite（α′N）,γ′-Fe4N and CrN phases.By adding RE,the layer depth and surface microhardness of the layer can be increased by 46% and 100 HV0.1,respectively.At the same time,the wear resistance of the surface layer of the RE nitrocaburized steel can also be improved obviously.